Budda reject Hinuisim because he found the system of their religious beliefs and practices and experiences and modes of expression is vital to human survival and self understanding .The way the Hindu did self-imposed constraints beliveing that it woujld bring them greater freedom in various areas of their lives, such as increased clarity of thought and the ability to resist potentially destructive temptations he found them to be completely ineffective. This was one of the main reasons along with others. So yes it was the cast system was the biggest issue for him but others did follow.
Siddhārtha Gautama was his name also known as Ezekiel in the old testment or יחזקאל, Yehezkel,ذو الكفل,Dhū'l-Kifl.
It must be understood that Hinduism and Buddhism have been sharing the same culture for the last 2500 years, which means they share a common language (Sanskrit or Pali). Because of this historical situation there are many words used commonly by both which have led many scholars (especially Hindu scholar) to think that they mean exactly the same thing in Buddhism as in Hinduism, By extending this thinking, one arrives at the wrong conclusion that Buddhism is another form or revision or reformation of Hinduism.
First of all, it is wrong to say that Buddhism is either a branch or a formation of Hinduism, Buddhism is actually a paradigm shift from not only Hinduism but also all other religious systems. Secondly, words used commonly in both Hinduism and Buddhism do not mean the same thing, in fact very often they mean almost the opposite and certainly at all times they point at two different paradigms. Hinduism actually apperars to arrise after Buddhism. Because of the fact he traveled over northern India does not make it so. The Buddha was born in a Hindu family, just as Christ was born in a Jewish family.
Some people still argue that Buddhism was an offshoot of Hinduism and the Buddha was a part of the Hindu pantheon, a view which is not acceptable to many Buddhists. It is however widely accepted that Buddhism gained popularity in India because it released the people from the oppression of tradition and orthodoxy. So because of the popluarity of Buddhism Hinduism clamed that this was so.. Infact you see that it is still very deep in most teachings about this.
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